This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Topical microbicides represent an emerging strategy for the prevention of transmission of HIV and other sexually transmitted infections. A successful topical microbicide product will be applied prior to intercourse, without necessitating partner consent, and will be active against a variety of STIs, including HIV. It will be acceptable to potential users in terms of physical characteristics, availability, ease of use, safety and efficacy properties. We have utilized the macaque vaginal safety model (currently contracted by the NIH, HHSN266200700013C) to provide standardized preclinical safety data for numerous topical microbicide products in development. In the contract model, measures of product safety include cervicovaginal colposcopy, vaginal microbiologic evaluation, and vaginal pH monitoring. The model characterizes the vaginal environment's response to repeated topical product applications in the absence of the exogenous factors of intercourse and potentially infectious ejaculate. With this project, we have enhanced our standardized vaginal safety evaluations conducted in the pigtailed macaque model to include evaluations after sexual activity and with the presence of seminal fluid. With continued funding, we are collecting baseline data from a large cohort of female macaques assessing the cervicovaginal environment before and after mating. In addition, we are collecting parallel pre- and post-coital assessments, with a placebo gel (HEC universal placebo) in place. These studies provide urgently needed data regarding topical microbicide use with coital activity.